This invention relates to a magnetic head construction, and more particularly to a magnetic head construction used for a vertical magnetization system.
Previously, a magnetic recording system has been widely used in which a ring-type magnetic head with a gap is used. By this magnetic head, a magnetic recording medium is magnetized in the direction of the relative motion between the magnetic recording medium and the magnetic head. In this recording system, to accomplish high-density magnetic recording, it is necessary to reduce the gap width of the magnetic head to as narrow as possible. Therefore, at present, magnetic heads with a gap width on the order of about 0.3[.mu.] through 0.5[.mu.] are used. However, such a gap width is approximately the minimum width which can be attained by machining.
In order to accomplish high-density magnetic recording without using the magnetic head with a narrow gap, two types of new magnetic recording systems have been proposed. One of them is a magnetic recordig system wherein a magnetic head with a magnetic gap is used and the direction of the magnetic gap is perpendicular to the direction of the relative motion between the magnetic head and the recording medium. Such a magnetic recording system is disclosed in the Japanese Laid Open Publication No. Sho. 50-81505 and in U.S. Pat. No. 3,984,874. The other system which has been proposed is a so-called vertical magnetization system.
In the former system, although it is possible to increase the recording density, the system has a disadvantage that a number of recording signals are picked up at the same. As a result, the recording head can not be used as the reproducing head.
On the other hand, in the latter system, the magnetic head comprises a core having a coil, and a main magnetic pole which has a sharp edge and is arranged so as to face the coil. The magnetic recording medium is placed between the core and the main magnetic pole and, then, a recording magnetic field is produced between the core and the main magnetic pole. As a result, the effective component of the recording magnetic field is perpendicular to the magnetic surface of the magnetic recording medium, so that the magnetic recording medium is magnetized in accordance with the intensity of the effective component of the recording magnetic field. Although this system is capable of high density recording, since the magnetic path is open, it is difficult to read out the recorded signal.